1. Field of the Invention
The present invention relates to a bimetal steam trap used to discharge low temperature condensation from a steam system in response to the temperature of condensation.
2. Description of the Prior Art
Conventionally, a bimetal steam trap includes a temperature-responsive valve arrangement with a valve element which assumes an open position when the temperature of condensation is below a predetermined level. As described, e.g., in U.S. Pat. No. 3,362,636, the valve element is normally biased toward its open position by means of a spring, and can be brought into its closed position by the pressure of condensation within the steam trap when the valve element is released from the biasing force of the spring. Because the valve element is to be actuated in response to the temperature of condensation, the steam trap has incorporated therein a bimetallic column including a plurality of pairs of bimetallic discs loosely mounted on a supporting rod and superposed with the other. The bimetallic column is arranged such that when the temperature of condensation within the steam trap is above a predetermined level, the column is subjected to an axial thermal expansion generating an axial thrust which overcomes the biasing force of the spring. With the conventional arrangement, however, because the valve element is axially connected with the rod supporting the bimetallic column by means of a connecting ring, not only the assembly of these components is troublesome and cannot be effected with a high productivity, but also it becomes very difficult to displace the valve element in precise alignment with the valve opening, under the presence of unavoidable manufacturing tolerance, so that an intended accurate operation of the steam trap can hardly be achieved.